This invention relates to noise reduction and vibration damping compositions based on blends of certain ethylene polymers with a vinyl chloride polymer and with mica.
Noise reduction and vibration damping compositions based on various polymers or polymer blends with inorganic fillers such as, for example, barium sulfate, calcium carbonate, lead salts, and even mica are known. Especially see Japanese patent applications (Kokai) Nos. 58-141230, 58-124923 (both Dainihon Ink Chemical Company), and 58-206660 (Sumitomo Chemical Company) as representative of such art. They can be used in numerous applications, including automobile carpets, plant motor enclosures, building soundproofing panels, etc. Depending on their intended use, such compositions may have to meet certain special performance requirements, such as. e.g., fabricability into sheets or panels and flexibility of such fabricated articles within particular temperature ranges, in addition to providing satisfactory noise reduction and vibration damping. For example, soundproofing mats for automotive use, which are placed in the engine compartment or under the hood of an automobile must be able to withstand high temperatures for prolonged periods without suffering heat-caused deterioration. They also must be able to withstand temperatures such as may be encountered in winter in cold climate when the automobile is parked outdoors for a prolonged period. While some of the currently used commercial products provide adequate performance within reasonable temperature ranges, they are not suitable for application in continuous use under harsh environmental conditions. New, improved compositions are therefore sought for such use.